Logic analyzers are versatile tools that help engineers with technical processes such as embedded software debugging, design verification, and digital hardware debugging. Unfortunately, some engineers opt for digital oscilloscopes to perform these functions instead of buying a logic analyzer. That mostly happens because they are familiar with oscilloscopes. However, advancements in logical analyzers have made them the ideal tools for digital debugging and verification. Purchasing them is an excellent idea. Here are 6 things you should know about logic analyzers before buying one.
- Signal Integrity
Discovering the cause of signal-integrity problems is possible through direct observation and measurements. Logic analyzers measure these signals. They are especially useful when it comes to troubleshooting integrity problems in complex systems. However, not every logic analyzer is suitable for this purpose because of high digital data rates. You should also note that most signal analyzers today have triggers detecting specific events that interfere with signal integrity.
- Setup and Hold
Setup time refers to the minimum time that input data should be valid prior to the clock edge shifting it into the device. It should be stable as well. Hold time refers to the minimum time that the data ought to valid and stable after the clock edge happens. Setup and hold requirements have narrowed over the years. They have narrowed so much that detecting and capturing these events is difficult for conventional general-purpose logic analyzers. However, logic analyzers with sampling resolutions at sub-nanosecond level can detect them.
- Computing Buses
High-speed computing buses are in a constant state of evolution. This evolution is driving the need for improvements in timing resolutions in logic analyzers. Interestingly, evolving high-speed communications devices are prompting this change in logic analyzers as well. Does the analyzer you have in mind have these improvements? High-speed buffer memories are one way of solving this issue. Remember, a high-speed buffer memory captures data at higher intervals around the device’s trigger point than a low or moderate one does.
- Memory Acquisition
The main acquisition memory in logic analyzers stores a comprehensive and long record of signal activity. However, some logic analyzers capture information at a multi-gigahertz rate across tens of channels. They accumulate these results in an extended record length. Ask whether the logic analyzer before you capture information at a high rate before you buy it. Only buy analyzers that have an adequate level of memory acquisition so that it does not become a problem in the future.
- Timing Probe
Some analyzers require a connection to a separate probe so that it can acquire the timing information that you need from it. Usually, they require separate acquisition hardware as well. Check the analyzer you want to buy to see if it requires a separate connection. More specifically, does it require one connection between the SUT and a timing module? Does it also require a second probe connection between the same test points and a state module? The technical name for these connections is double probing.
- State & Timing Data
Correlated state & timing data facilitates hardware and software debugging. Another name for this debugging process is system integration. Remember, detecting a problem as an invalid state on a computing bus is possible. Problems such as a setup & hold timing violation may lead to this kind of flawed detection. Isolating these problems is time-consuming if the logic analyzer you are using is incapable of capturing state & timing data simultaneously.